DirectionsPreheat oven to 350°. Combine flour, cocoa, baking soda, baking powder, and salt in a large bowl. Set aside.

Beat the butter and sugar with a mixer at medium speed until light and fluffy. Add the egg and vanilla; beat well. Gradually add the flour mixture, beating until blended. Stir in chocolate chips and walnuts (if using).

Drop by rounded tablespoonfuls 1 1/2 inches apart onto a baking sheet lined with parchment paper or a silicone mat. Bake at 350° for 12-14 minutes. Cool on the pan for 2 minutes or until firm. Remove cookies to a wire rack to cool completely.